Question
A subscription is flagged with a blue lock saying:
The subscription is locked for synchronization: It is excluded from syncing with the service plan because the subscription parameters were customized.
How to synchronize locked subscriptions with their service plans?
Answer
Synchronizing a subscription with its service plan via Plesk
Log in to Plesk.
Go to Subscriptions > example.com.
Click Unlock & Sync in the Account section on the right.
Note: If the Account section is hidden, click on the 
button in the upper right corner.
